A storage system of one type includes a host device and one or more storage devices connected to the host device. In such a storage system, the host device manages and controls access to the one or more storage devices, i.e., data writing to and data reading from the one or more storage devices. Furthermore, there is a data storage network, in which a plurality of the storage systems is connected with each other. In such a data storage network, a host device of a storage system is able to access a storage device of another storage system in the data storage network.